Physics Help Needed Plez Look :>?

Question

1} A person in a rocking chair completes 23 cycles in 38 s. What is the period and frequency of the rocking?

2} The position of a mass oscillating on a spring is given by x = (3.9 cm) cos [2t / (4.40 s)].

(a) What is the period of this motion?
(b) What is the first time the mass is at the position x = 0?

3.)A typical tidal wave (tsunami) can have a speed of 739 km/h and a wavelength of 305 km. What is the frequency of such a wave?

4.)In a pig-calling contest, a caller produces a sound with an intensity level of 110 dB. How many such callers would be required to reach the pain level of 120 dB?
Two musicians are comparing their clarinets. The first clarinet produces a tone that is known to be 509 Hz. When the two clarinets play together they produce 8 beats every 2.00 seconds. If the second clarinet produces a higher pitched tone than the first clarinet, what is the second clarinet's frequency? (Express your answer to the nearest hertz.)

6.)A 89 kg person sits on a 3.5 kg chair. Each leg of the chair makes contact with the floor in a circle that is 1.7 cm in diameter. Find the pressure exerted on the floor by each leg of the chair, assuming the weight is evenly distributed
5.)

Answer 1

Wow, 5 problems?!
1} A person in a rocking chair completes 23 cycles in 38 s. What is the period and frequency of the rocking?
Period: (38/23)s
Frequency: (23/38) s^-1

2} The position of a mass oscillating on a spring is given by x = (3.9 cm) cos [2t / (4.40 s)].
(a) What is the period of this motion?
4.40*pi (s), with pi = 3.1415926535....
(b) What is the first time the mass is at the position x = 0?
1.10*pi (s)

3.)A typical tidal wave (tsunami) can have a speed of 739 km/h and a wavelength of 305 km. What is the frequency of such a wave?
For any wave, the formula between the velocity, frequency and wavelength is: f = v/λ
where f is the frequency in 1/s or Hz, v the speed or velocity in m/s, and λ the wavelength in m. Now you please do the math.

4.)In a pig-calling contest, a caller produces a sound with an intensity level of 110 dB. How many such callers would be required to reach the pain level of 120 dB?
That means the intensity level needs to be one order of magnitude higher: 10 such callers.

Two musicians are comparing their clarinets. The first clarinet produces a tone that is known to be 509 Hz. When the two clarinets play together they produce 8 beats every 2.00 seconds. If the second clarinet produces a higher pitched tone than the first clarinet, what is the second clarinet's frequency? (Express your answer to the nearest hertz.)
Of course it is 509+8/2 = 513 (Hz)

6.)A 89 kg person sits on a 3.5 kg chair. Each leg of the chair makes contact with the floor in a circle that is 1.7 cm in diameter. Find the pressure exerted on the floor by each leg of the chair, assuming the weight is evenly distributed
The total area of 4 legs to contact with the floor is:
4*3.14159*0.0085^2 = 0.000908 (m^2)
The pressure is (89kg + 3.5kg)/0.000908m^2 = 1.0x10^5 kg/m^2, no matter which leg. I only take 2 significant figures since the data given is also with 2 significant figures.

Answer 2

That question is not Answerable IMO. Define biological damage. How fast are the neutrons? (what is their energy?)